This invention relates to rapid egress systems that are suitable for use in light general aviation and commercial aircraft that demand egress systems that are reliable, lightweight, and do not require redesign of existing airframes. Existing raipd egress systems have been developed with aircraft of different performance parameters in mind, and do not adequately meet the unique needs of the aircraft industry in three major aspects: design, weight and cutting/jettisoning effectiveness.
Existing rapid egress system are activated by either mechanical or pyrotechnic devices; both systems detach enframed egress panels from an airframe. Supporting frames for the egress panels are incorporated into the airframes to maintain structural integrity while the egress panels are detached. Incorporating the supporting frames into existing designs is costly, and requires substantial and costly stress analysis of the resulting structures because of changes in the distribution of forces within the entire airframe.
Weight is a major concern in designing light, general aviation aircraft due to relatively small power plants, and market demands for improved performance for both general and commercial aircraft. Mechanically activated systems are undesirable because they require linkage and piston-cylinder assemblies driven by auxiliary power sources which substantially increase the airframe's weight. Supporting frames designed to be a major load carrying element in an airframe are also undesirable for similiar reasons.
Since design and weight criteria restrict the use of supporting frames which protect egressing objects from roughly cut edges at the egress area periphery, it is important for the cutting means to produce a smoothly cut edge. Rough edges increase the potential of cutting an egressing object or preventing egress by snagging the object. Though flexible linear-shaped charges have been held against an airframe to cut the periphery of an egress area, there is not teaching of a structure which improves cutting effectiveness, smoothly cuts the airframe and acts to assist the jettisoning of the severed portion of the skin/airframe.
Accordingly, it is an object of this invention to provide a light-weight structure which smoothly cuts an airframe along the periphery of an egress area, and jettisons that portion of the airframe within the periphery away from the aircraft.
Another object of the invention is to provide an external containment cell bounded by the airframe's skin and reaction surfaces which extends along the egress area periphery for increasing the cutting effectiveness of a pyrotechnic device.
Another object of the invention is to jettison that portion of the airframe within the egress area periphery by transferring the explosive forces received by the reaction surface to that portion of the airframe within the egress area periphery.
A prime object of the invention is to provide a lightweight structure which can be added to an existing airframe that shields the airframe's interior from explosive forces and debris caused by detonation of the pyrotechnic device.
Another object of the invention is to provide a mechanism which will have no loss in effectiveness upon the airframe's load carrying characteristics.
A further object of the invention is to shield the airframe's interior while that portion of the airframe within the egress area periphery is jettisoned.
Yet another object of the invention is to provide a quick and easy means to activate the egress system with a bellcrank and lanyard detonator assembly.
Still another object of the invention is to provide a fine wire mesh screen over glass areas within the egress area periphery that will not interfere with vision, and carries any broken glass with that portion of the airframe which is jettisoned.